565 research outputs found

    A mixed-mode bending apparatus for delamination testing

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    A mixed-mode delamination test procedure was developed combining double cantilever beam mode I loading and end notch flexure mode II loading on a split unidirectional laminate. By loading the specimen with a lever, a single applied load simultaneously produces mode I and II bending loads on the specimen. This mixed mode bending (MMB) test was analyzed using both finite element procedures and beam theory to calculate the mode I and II components of strain energy release rate, G sub I and G sub II, respectively. The analyses showed that a wide range of G sub I/G sub II ratios could be produced by varying the applied load position on the loading lever. As the delamination extended, the G sub I/G sub II ratios varied by less than 5 percent. The simple beam theory equations were modified to account for the elastic interaction between the two arms of the specimen and to account for shear deformations. The resulting equations agreed closely with the finite element results and provide a basis for selection of G sub I/G sub II test ratios and a basis for computing the mode I and II components of measured delamination toughness. The MMB specimen analysis and test procedures were demonstrated using unidirectional laminates

    Analysis of the Health Product Profile Directory - a new tool to inform priority-setting in global public health

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    Background: The Health Product Profile Directory (HPPD) is an online database describing 8–10 key characteristics (such as target population, measures of efficacy and dosage) of product profiles for medicines, vaccines, diagnostics and other products that are intended to be accessed by populations in low- and middle-income countries. The HPPD was developed by TDR on behalf of WHO and launched on 15 May 2019. Methods: The contents of the HPPD were downloaded into an Excel™ spreadsheet via the open access interface and analysed to identify the number of health product profiles by type, disease, year of publication, status, author organization and safety information. Results: The HPPD contains summaries of 215 health product profiles published between 2008 and May 2019, 117 (54%) of which provide a hyperlink to the detailed publication from which the summary was extracted, and the remaining 98 provide an email contact for further information. A total of 55 target disease or health conditions are covered, with 210 profiles describing a product with an infectious disease as the target. Only 5 product profiles in the HPPD describe a product for a non-communicable disease. Four diseases account for 40% of product profiles in the HPPD; these are tuberculosis (33 profiles, 15%), malaria (31 profiles, 14%), HIV (13 profiles, 6%) and Chagas (10 profiles, 5%). Conclusion: The HPPD provides a new tool to inform priority-setting in global health — it includes all product profiles authored by WHO (n = 51). There is a need to standardise nomenclature to more clearly distinguish between strategic publications (describing research and development (R&D) priorities or preferred characteristics) compared to target product profiles to guide a specific candidate product undergoing R&D. It is recommended that all profiles published in the HPPD define more clearly what affordability means in the context where the product is intended to be used and all profiles should include a statement of safety. Combining the analysis from HPPD to a mapping of funds available for R&D and those products in the R&D pipeline would create a better overview of global health priorities and how they are supported. Such analysis and increased transparency should take us a step closer to measuring and improving coordination of efforts in global health R&D

    Flight Measurements of Flying Qualities of a P-47D-30 Airplane (AAF No. 43-3441) to Determine Longitudinal Stability and Control and Stalling Characteristics

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    Flight tests have been made to determine the longitudinal stability and control and stalling characteristics of the P-47.E-30 airplane. The teat results show the airplane to be unstable stick free in any power-on condition even at the most forward center-of-gravity position tested. At the rearward center-of-gravity position tested the airplane also had neutral to negative stick-fixed stability with power on. The characteristics in accelerated flight were acceptable at the forward center-of-gravity position at low and high altitudes except at high speed where the control-force variations with acceleration were high. At the rearward center-of-gravity position, elevator-force reversals were experienced in turns at low speeds, and the force per g was low at all the other speeds. Ample stall warning was afforded in all the conditions tested and the stalling characteristics were very satisfactory except in the approach and wave-off conditions

    The Role of Organizational Affiliations and Research Networks in the Diffusion of Breast Cancer Treatment Innovation

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    The National Institutes of Health (NIH) sees provider-based research networks and other organizational linkages between academic researchers and community practitioners as promising vehicles for accelerating the translation of research into practice. This study examines whether organizational research affiliations and teaching affiliations are associated with accelerated diffusion of sentinel lymph node biopsy (SLNB), an innovation in the treatment of early-stage breast cancer

    Race and age disparities in receipt of sentinel lymph node biopsy for early-stage breast cancer

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    To evaluate differences in use of sentinel lymph node biopsy (SLNB) by age and race in Medicare recipients with early-stage breast cancer, we examined Surveillance, Epidemiology and End Results—Medicare linked data for women undergoing breast conserving surgery for stage I or II breast cancer, including axillary staging, between January 2000 and December 2002. Multivariable generalized linear modeling with generalized estimating equations was used to identify predictors of receiving SLNB versus standard axillary lymph node dissection as the primary axillary staging modality. Women were significantly less likely to receive SLNB as their primary staging procedure if they were African American (OR 0.65), greater than 80 years of age (OR 0.71 vs. age <70), or dually eligible for Medicare and Medicaid (OR 0.61). Tumor characteristics, including well-differentiated histology and stage I disease, were associated with increased likelihood of SLNB, but estrogen receptor status was not a significant predictor. Women treated at an institution affiliated with an NCI cooperative research group had significantly greater likelihood of receiving SLNB (OR 2.31). Likelihood of receiving SLNB increased for women diagnosed in 2001 and 2002 compared with 2000. Significant disparities exist in receipt of SLNB in the Medicare population, with African Americans, the elderly, and economically disadvantaged patients being less likely to receive this innovative and morbidity-sparing procedure. These findings continue a previously observed pattern of reduced access to state of the art breast cancer care among underserved populations

    Towards harmonization of microscopy methods for malaria clinical research studies

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    Microscopy performed on stained films of peripheral blood for detection, identification and quantification of malaria parasites is an essential reference standard for clinical trials of drugs, vaccines and diagnostic tests for malaria. The value of data from such research is greatly enhanced if this reference standard is consistent across time and geography. Adherence to common standards and practices is a prerequisite to achieve this. The rationale for proposed research standards and procedures for the preparation, staining and microscopic examination of blood films for malaria parasites is presented here with the aim of improving the consistency and reliability of malaria microscopy performed in such studies. These standards constitute the core of a quality management system for clinical research studies employing microscopy as a reference standard. They can be used as the basis for the design of training and proficiency testing programmes as well as for procedures and quality assurance of malaria microscopy in clinical research.Publisher PDFPeer reviewe

    Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

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    A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets
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